Re: JetPacks vs. AirCars

Michael S. Lorrey (
Mon, 23 Aug 1999 00:01:19 -0400 wrote:
> In a message dated 99-08-22 18:30:00 EDT, (Philip Witham)
> wrote:
> > And, yes, Spike, I think a nanotech Aircar can have a low rotor disc
> loading
> > like a helicopter, even a non-nanotech aircar. By the way, a ducted fan
> like
> > the Moller designs use has an effective area of the inlet area of the duct,
> > if it's done just right, not just the fan area. Not that I like the Moller
> > designs. I want 200,000 rotors about 7mm in diameter, spinning at >10,000
> > rotations per second (two blades each), to get the fundamental rotor noise
> > frequency above human hearing range. This works out to be the area of a
> > Cadillac or standard parking space, and a disc loading like a helicopter.
> >
> > One of these days I'll write up an aircar paper for this group - I've been
> > running simulations of automated air-traffic control - self piloting
> aircars -
> > fun stuff.
> You might want to check out J. Storrs Hall's paper on nanotech aircars. He
> comes to basically the same conclusions regarding size, efficiency and low
> noise, by using LOTS of VERY small rotors.

Just saw a bit on TV about the micro-air vehicles being developed. Seems as though normal props, etc. don't cut it at such small scales, they lose efficiency, which is why insect wings use boundary layer separation vortices to generate their lift, rather than laminar flow as a normal air foil uses.

My personal fav is an ultralight orinthopter suit. Using carbon construction, imagine a 20 lb contraption (engine weight not included) with a 25 foot wingspan powered by a 5 hp rotary engine.

Mike Lorrey